Art of printing



Se t, 2 1924. 1,507.358

J. A. IMHOF ART OF PRINTING Filed April '7, 1922 2 Sheets-Sheet 1 I Gum se t. z 1924.

1,507,358. J. A. IMHOF ART OF PRINTING Filed April 7, 1922 2 Sheets-Sheet 2 Patented sea. 2.1924.

units!) STATES JOSEPH A. FMHOF, OF NEW YORK, N. Y., ASSIGNOB TO INVISIBLE COLOR PRINT OOR- POBATION, 0E NEW YORK, N. Y., A CORPORATION OF NEW YORK.

1,507,358 PATENT OFFICE.

ART OF FRINTING.

Application filed April 7, 1928. Serial No. 550,305.

To all whom it may concern:

Be it howls that l, JosErH A. lmnor, a citizen of the United States, and a resident of NewYork city, in the borough of Manhattan, county and State of New York, have invented certain new and useful Improvements in the Art of Printing, of which the following is a specification.

This invention relates to the art of printing and has for its main feature and object the printing of a picture or other matter in an apparently uniform color but having latent and substantially invisible color that is released and made visible upon application to the printed surface of a solvent, such as water. The solvent inay be applied to the printed surface by'means of a brush and each colored part may be, separately developed but preferably the latent color is so applied that it covers substantially the entlre printed surface and upon the application thereto of a solvent, each of the, particles of coloring matter distributed over the surface will release just enough color to cover the immediatel adjacent surface, so that immersion of-tlie printed surface in water will develop all the colors and will retain the colors in the proper place appro riate to the picture or design to be produce The process of producing prints of this character is disclosed in Patent No. 1,384,663 of July 12, 1921 granted to me.

Figure 1 is a viewof a complete picture as it will appear after successive superimposed impressions have been made.

Fig.2 is a view of a partial image of the icture in Fig. 1 having latent blue colorlng matter...

ig. 3 is a view of a partial image of the picture in Fig. 1 having latent yellow color- 1n matter.

ig. 4 is a view of a partial image of the picture of Fig. 1 having latent red coloring matter.

Fig. 5 is a view of a partialimage of the picture of Fig. 1 devoid of latent coloring matter and printed in insoluble ink that acts as a dam between differently colored parts of the picture to prevent intermingling of the colors.

-' Fig. 6 is a. View of a'surface contain a dam of varnish or other insoluble materia applied to the picture to prevent intermingling of colors.

Fig. 7 is a view of a surface having still another form of dam of varnish, ink or other insoluble material to prevent or disguise overfiow of color.

in preparing the picture, the artist makes separate drawings of the blue, yellow and red partial. images as shown in Figs. 2, 3 and 4-. These drawings are however made in black or other uniform color, and are reproduced by means of photo-engraving and made into half tone plates or their equivalent such asplates made by the Ben Day process. Three separate impressions are then su erimposed on the same surface resulting -1n the picture shown in Fig. 1. In printing the several partial images soluble anilin color is ground in, or otherwise thoroughly mixed with, the insoluble ink of uniform color, blue for the partial image of Fig. 2; yellow for the partial image of Fig. 3 and red for the partial image of Fi 4c. 7

it has been found that a practically perfeet-disguise may be obtained by mixing in addition to the insoluble ink and the coloring matter a second insoluble ink of a. color difierent from the first mentioned insoluble ink and different from the coloring matter. F or instance, the ink,used to print the blue image of Fig. 2 may have mixed with it a certain amount of red oil ink; the ink used to print the yellow image of Fig. 3 may have a certain amount of blue oil ink; and the ink used to print the red image of Fig; 4: may have a certain amount of blue oil mk. The result of adding the insoluble colored ink is to obtain a substantially uniform tone on the picture shown in Fig. 1 before development, thereby rendering detection of the latent color practicallyimpossible.

A preferred formular for mixing the ink for producing such a design is as follows:

for the yellow image, 14 parts aniline yel-' merelyl partial images. These partial images contain com onents of light and shade and of latent co or, and, where overlapping of partial images occurs, as in the case of the face 1 of the boy, or of the oranges 2 on the tra regard must be had to the total effect of 'ght and shade in overlapping parts of the image; -That is to say, the sum of the shade and light com onents of overlapping parts must equal t e correct amount of ight and shade in the complete picture, and the artist must therefore not put the complete shade and light in a partial image where overlapping occurs. Thus in Figs. 3 and4 each incomplete ima e carries an in complete component of 'lig t and shade in the face 1 and oranges 2. But here an other factor enters. We are dealing not with incomplete components of light and s ade but also with the superimposing of colors and the amount of li ht and shade of each partial image depen s not merely upon the number of-partial images that are necessary to produce a complete image but also upon theamount of coloring matter to be supplied by a partial image. Thus in the case of the oranges 2, the amount of yellow required is considerable as shown by Fig. 3, while the amount of red required, as shown by Fig. 4, is slight. The proportion of shade of partial image Fig. 3 is therefore greater than the proportion of shade of par- I tial image Fig, 4, so far as oranges 2 are con-- eral tone e cerned. In other words, where overlapping occurs, the'total amount of shade required is divided in proportion to, the amount of latent color required to be carried in the several partial images, because the insoluble ink carries the soluble coloring matter.

Insome instances it is preferred to add, to the three superimposed impressions heretofore mentioned, an im ression like that shown in Fig. 5. This impression constitutes a dam of insoluble material between the different partial images. This dam may, as in the example shown, constitute a part of the design of complete image and may therefore be printed with insoluble ink. If a dam such as is shown in Fig. 5 is used printed with insoluble ink, it is desirable to add a sufiicient amount of red oil ink so that this im ression also will match the gen- Eect of the three other impressions. In other cases where the character of the design does not lend itself to having a dam in dead black or other uniform color, said dam may printed in insoluble 'varnish, or other material that will be practically invisible.

In Fig. 6 is shown a damof insoluble varnish which is in the form of an outline surrounding the picture and also separating the constituent arts of the pictures. This dam is practice. y invisible. In Fig. 7 the 'ducing requisite latent coloring other the design of Fig. 6.

By the process above described singularlybeautiful efiects may be produced, and it is a remarkable fact I find that the pictures may be developed by immersion substantially without intermingling of colors. This 'is facilitated in some instances by retarding the solution of the soluble coloring matter of the different partial images. This ma be accomplished by mixing gum arabic with the soluble coloring matter in different proportions so that upon immersion successive color releases are obtained. It is also important that hard coated paper be used on which to print the image if the best results are to be obtained. I prefer to use a smooth finish or coated stock. a

I claim: v

1. As a new article of manufacture, a design, produced from half-tone plates or the like, of apparently uniform color but carrying soluble coloring matter in substantially invisible form comprising: a plurality of partial images printed. in su erimposed and partially overlapping relation with insoluble ink of a substantially uniform color the insoluble ink of the several partial images containing difi'erently colored soluble coloring matter, the overlappin of the coloring matter producing requisite latent coloring other than that of the primary colors. 1

2. As a new article of manufacture, a design, produced from half-tone plates or the like, of apparently uniform color but carr ing soluble coloring matter in substantial y invisible form comprising: a plurality of partial images printed in su rim osed and partially overlapping relation Wlth insoluble ink of a substantially uniform color the insoluble ink of the several partial images containing differently colored soluble coloring matter, the overlappin of the insoluble ink producing requisite li t and shade and the overlapping of the coloring matter roan that of the primary colors.

3. As a new article of manufacture, a design of a parently uniform color but carrying solub e coloring matter of various colors in substantially invisible form comprising:

a plurality of partial images printed to form a picture, each partial ima e rinted with insoluble ink of a given co or aving an admixture of soluble colorin matter of a different color and insoluble i of still another color.

4. As a new article of manufacture, a design of apparently uniform color but carrying solub e coloring matter of various colors in substantially invisible form comprising: a plurality of partial images printed to form a picture, each partial image i: ink being of a uniform color in all of the printed with insoluble ink of a given color images and the last mentioned insoluble ink having an admixture of soluble coloring being of a color in each partial image oorre- 10 matter of a diflerent color and insoluble ink spondin to the soluble coloring matter of v of still another color, the first mentioned one of t e other partial images.

Si ed at New York city, in the borough partial images, the coloring matter of each of nhattan, county and State of New partial image being of a color contrasting York, this 6 day of April, 1922. with the coloring matter of the other partial JOSEPH A. IMHOF. 

